Heat sink with columnar heat dissipating structure

ABSTRACT

A heat sink includes a base and a heat dissipating structure composed of columnar heat dissipating units integrally formed on the base. Air stream gaps communicating with the dissipating units, each having opposite first and second sides, are formed. The first side is an arced surface structure, and the second side has a flow-guide projection. Furthermore, the dissipating units facing the same direction are arranged in an array. Alternatively, first sides of the outermost layer of the dissipating units face directions away from the inner layer of the dissipating units, and the corresponding directions of the first sides of the dissipating units from the outer to inner layers gradually deflect. The air streams flowing in various directions have the higher possibility of entering the dissipating structure and are dispersed. Thus, the time and possibility for the air to contact the dissipating units are increased, and the dissipation efficiency is increased.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a technological field of a heat sink, and more particularly to a heat sink with columnar heat dissipating structures, which can be applied to a LED road lamp, a solar thermoelectric conversion apparatus or any other apparatus or element requiring heat dissipation by way of heat transfer.

2. Related Art

A typical light-emitting diode (LED) apparatus, such as a LED road lamp, generates a lot of heat with the elapse of time after being turned on. The high-temperature causes poor effects, such as the lowered working efficiency and endurability, to the LED apparatus. Thus, the typical LED apparatus is almost equipped with a heat sink or a heat dissipating system to perform the heat dissipation. The frequently seen outdoor heat sink is composed of many heat dissipating fins, which are arranged in parallel at the same level so that the heat is dissipated to the atmosphere through the surface of each heat dissipating fin. In addition, the flowing air streams can take the heat away through the gaps between the heat dissipating fins.

Because the heat sink is exposed to the atmosphere, the rain, dust or leaves may directly fall on the heat dissipating fins. Therefore, in order to prevent the problems, such as the unpredictable leakage current, the short-circuit condition or the fan failure, the outdoor heat sink is not suitable for the working in conjunction with the fan. In order to enhance the dissipation effect of the heat sink, the solution of enhancing the dissipation effect of the current outdoor heat sink is to enlarge the heat dissipating surface area.

The method of enlarging the dissipation area is to increase the number of the heat dissipating fins. However, increasing the number of heat dissipating fins would decrease the gaps between the neighboring heat dissipating fins. In addition, the parallel and contour structure of the heat dissipating fins disables the heat inside the inner heat dissipating fins from being easily dissipated. Thus, the heat accumulation is produced, and the heat dissipation effect cannot be substantially enhanced.

Also, the too-dense heat dissipating fins increase the possibility of the accumulation of the dust or leaves, and disable the flowing air streams from easily passing through the gaps between the heat dissipating fins so that the heat dissipation efficiency of the heat sink is poor.

Furthermore, the channels between the heat dissipating fins face the same direction, and the fin surface faces the direction perpendicular to the channel. Therefore, when the flowing air streams blow toward the fin surface, the flowing air streams cannot easily enter the channel, and the efficiency of the heat sink is reduced.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a heat sink having a columnar heat dissipating structure, so that the flowing air streams can rapidly flow within the heat sink in many directions and the heat sink has the higher heat dissipation efficiency.

According to the above-identified object and effect, the invention discloses a heat sink including a base and a heat dissipating structure, which is composed of a plurality of heat dissipating units. Each heat dissipating unit is integrally formed with and stands on the base. The heat dissipating units are columnar. An air stream gap is formed between the neighboring heat dissipating units and the air stream gaps communicate with one another. The heat dissipating unit has a first side and a second side. The first side is an arced surface structure, and the second side is disposed opposite the first side and may have a flow-guide projection.

Furthermore, the heat dissipating units are arranged in an N-layer phalanx including an outermost layer defined as a first layer, and an innermost layer defined as an N^(th) layer. The first sides of the first layer of the heat dissipating units in various facing directions are arced surface structures and face the directions away from the N^(th) layer of the heat dissipating units. In addition, the corresponding directions of the first sides of the heat dissipating units in various facing directions gradually deflect from the first layer to the N^(th) layer.

Thus, the flowing air streams in various directions have the higher possibility of entering the heat dissipating structure and of being dispersed, so that the time and possibility for the air streams or gas streams to contact the heat dissipating surface are lengthened and increased, respectively, and the heat dissipation efficiency is increased.

Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the present invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention.

FIG. 1 is a pictorial view showing the invention.

FIG. 2 is a schematic top view showing the invention.

FIG. 3 is a schematic plane view showing another arrangement of the heat dissipating units of the invention.

FIG. 4 is a pictorial view showing another heat dissipating unit of the invention.

FIG. 5 is a pictorial view showing still another heat dissipating unit of the invention.

FIG. 6 is a schematic top view of the invention.

FIG. 7 is a schematic plane view showing still another arrangement of the heat dissipating units of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.

Referring to FIG. 1, a heat sink 10 includes a base 12 and a heat dissipating structure 14. The heat dissipating structure 14 is composed of a plurality of columnar heat dissipating units 16. Each heat dissipating unit 16 is integrally formed with and stands on the base 12.

Also, an air stream gap 18 is formed between the neighboring heat dissipating units 16, and the neighboring air stream gaps 18 communicate with each other to form a through channel.

The heat dissipating unit 16 has a first side 22 and a second side 24, wherein the first side 22 is an arced surface structure, and the second side 24 is disposed opposite the first side 22.

Furthermore, the arced surface structure of the first side 22 shown may be a portion of the circumference, and the arc in this preferred embodiment is a minor arc smaller than a semi-circle. The second side 24 is a plane structure.

As shown in FIG. 2, the heat dissipating units 16 are arranged in an N-layer array (a three-layer phalanx is shown in the drawing) having an outermost layer defined as a first layer and an innermost layer defined as an N^(th) layer. The first sides 22 (arced surface structures) of the first layer of the heat dissipating units 16 in various facing directions face the directions away from the N^(th) layer of the heat dissipating units 16.

The heat dissipating units 16 arranged in the phalanx are only illustrated in one embodiment. The heat dissipating units 16 may also be arranged in the form of concentric circles or any other geometric array.

Also, for each layer of the heat dissipating units 16 on the same surface, the corresponding directions of their first sides 22 gradually deflect from the first layer to the N^(th) layer. For example, in the same facing direction, the differences between the outward directions of the first sides 22 of the first layer of the heat dissipating units 16 and the first sides 22 of the N^(th) layer of the heat dissipating units 16 are equal to 90 degrees.

When the flowing air streams reach the windward surface of the heat dissipating structure 14, the flowing air streams may enter the heat dissipating structure 14 through the air stream gaps 18. More particularly, when the flowing air streams contact the first sides 22 of the heat dissipating units 16, the flowing air streams can slide into the air stream gaps 18 along the arced surface structures of the first sides 22.

During the flowing process of the flowing air streams in the heat dissipating structure 14, the flowing air streams continuously contact the layers of the heat dissipating units 16 and change the flow directions. So, the possibility and the contact time for the flowing air streams to contact the heat dissipating unit 16 are increased and lengthened, respectively, and the heat dissipation efficiency is enhanced.

As shown in FIG. 3, the heat dissipating units 16 may also be arranged in a neat array, wherein the first sides 22 of the heat dissipating units 16 face the same direction.

As shown in FIG. 4, the bottom of the second side 24 of the heat dissipating unit 16 may have a flow-guide projection 26, which has two convex flow-guide surfaces 28. After the flowing air streams flow through the first side 22, the flowing air streams at the bottom may rise through the convex flow-guide surface 28. Consequently, the lower air or gas may have the higher fluidity and can push the upper air or gas to disturb the air to flow in various directions or to escape from the top end of the heat dissipating unit 16.

As shown in FIG. 5, the first side 32 of the heat dissipating unit 30 in another embodiment of the invention is an arced surface structure, the second side 34 thereof is also the arced surface structure, and the curvature of the second side 34 is different from that of the first side 32. Furthermore, the first side 32 is engaged with the second side 34 through the flow-guide inclined surface 36 so that the heat dissipating unit 30 is formed with the wing-shaped columnar structure.

As shown in FIG. 6, the heat dissipating unit 30 of the wing-shaped columnar structure is integrally formed on a base 12. The heat dissipating units 30 are arranged in an N-layer phalanx, and the first sides 32 of the first layer (outermost layer) of the heat dissipating units 30 face outwards. In addition, the heat dissipating units 30 with the same facing direction gradually deflect from the first layer to the N^(th) layer (innermost layer). For example, the facing direction of the first layer of the heat dissipating unit 30 differs from the facing direction of the N^(th) layer of heat dissipating unit 30 by 90 degrees.

The flowing air streams may flow in the air stream gaps 38 between the neighboring heat dissipating units 30. Because the heat dissipating units 30 have the wing-like shape, the air/gas can flow more rapidly, and can continuously contact various layers of the heat dissipating units 30 and flow in various directions, so that the heat dissipation efficiency can be enhanced.

As shown in FIG. 7, the heat dissipating units 30 may also be arranged in a neat array, wherein the first sides 32 of the heat dissipating units 30 face the same direction.

Because the heat sink of the invention may be applied to an outdoor opto-electronic apparatus, such as a LED road lamp, the base 12 in each of FIGS. 2, 3, 6 and 7 may be an upper lamp shell of the LED road lamp, and the heat dissipating structure and the upper lamp shell are integrally formed.

While the present invention has been described by way of examples and in terms of preferred embodiments, it is to be understood that the present invention is not limited thereto. To the contrary, it is intended to cover various modifications. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications. 

1. A heat sink, comprising: a base; and a heat dissipating structure comprising a plurality of heat dissipating units being integrally formed with the base and standing on the base, wherein: the heat dissipating units are columnar, an air stream gap is formed between the neighboring heat dissipating units and the air stream gaps communicate with one another; and the heat dissipating unit has a first side and a second side, the first side is an arced surface structure, and the second side is disposed opposite the first side.
 2. The heat sink according to claim 1, wherein the heat dissipating units of the heat dissipating structure are arranged in an array, and the first sides of the heat dissipating units face the same direction.
 3. The heat sink according to claim 1, wherein the heat dissipating units of the heat dissipating structure are arranged in an N-layer phalanx comprising an outermost layer defined as a first layer, and an innermost layer defined as an N^(th) layer, and the first sides of the first layer of the heat dissipating units in various facing directions face directions away from the N^(th) layer of the heat dissipating units.
 4. The heat sink according to claim 3, wherein the first sides of the heat dissipating units from the first layer to the N^(th) layer gradually deflect to change corresponding directions of the first sides of the heat dissipating units.
 5. The heat sink according to claim 4, wherein facing directions of the first sides of the first layer of the heat dissipating units of the heat dissipating structure in the same facing direction differ from facing directions of the first sides of the N^(th) layer of the heat dissipating units by 90 degrees.
 6. The heat sink according to claim 1, wherein a bottom of the second side of the heat dissipating unit has a flow-guide projection having two opposite convex flow-guide surfaces connected together.
 7. The heat sink according to claim 1, wherein two flow-guide inclined surfaces are formed between the first side and the second side of the heat dissipating unit, and the flow-guide inclined surface connects the first side to the second side.
 8. The heat sink according to claim 1, wherein the base is an upper lamp shell of a LED road lamp. 